The Visceral Slide Test for the Prediction of Abdominal Wall Adhesions: a Prospective Cohort Study

ORIGINAL ARTICLE East J Med 24(1): 91-95, 2019 DOI: 10.5505/ejm.2019.34966

The Visceral Slide Test For The Prediction of Abdominal Wall Adhesions: A Prospective Cohort Study

Isil Safak Yildirim1, Dogukan Yildirim2*, Seyma Yesiralioglu1, Sefik Eser Ozyurek1

1Department of Obstetrics and Gynecology, Bagcilar Training and Research Hospital, Istanbul, Turkey 2Department of Obstetrics and Gynecology, Kanuni Sultan Suleyman Training and Research Hospital, , Istanbul, Turkey

ABSTRACT An accurate prediction of abdominal wall adhesions would be extremely beneficial to help preventing injuries during the initial abdominal entry. Our aim was to evaluate the accuracy of the visceral slide test in predicting abdominal wall adhesions before surgery. One hundred fifty-five patients who underwent benign gynecologic surgery were prospectively enrolled. Seventy patients (45%) had previous baseline risk factors including abdominal surgeries, episodes of pelvic inflammatory disease [PID] or peritonitis. Eighty-five patients (55%) had no risk for intraabdominal adhesions. On the day of surgery, patients underwent the visceral slide test in ﬁve zones of the abdomen using ultrasonography, and a prediction of adhesions was made for each zone. Ultrasound findings were then compared with intraoperative visualization. A total of 112 laparotomies and 43 laparoscopies were performed. The use of the visceral slide test for the prediction of adhesions showed an overall accuracy of 86.5%, a sensitivity of 78.6%, a specificity of 88.2, a positive predictive value of 59.5%, and a negative predictive value of 94.9%. Our study suggests that the visceral slide test is an easy, non-invasive, and reliable method for predicting abdominal wall adhesions in women undergoing benign gynecologic surgery. Key Words: Visceral slide, ultrasonography, abdominal wall adhesions, laparoscopy

Introduction slide." A reduction or absence of visceral slide is suggestive of underlying abdominal wall Despite the advancements in surgical technology, adhesions. Thus, the visceral slide test could assist intraabdominal adhesions following surgery is still with preoperative surgical planning for a major concern for surgeons. Any inflammatory laparoscopy or laparotomy. process in the abdomen, including pelvic In this prospective cohort study, we evaluated the inﬂammatory disease (PID), endometriosis or use of the visceral slide test for the detection of peritonitis, may also lead to intraabdominal intraabdominal adhesions and compared the adhesions. Adhesions are pathologic formations of results with intraoperative findings in women fibrous scar tissue that adhere to abdominal wall undergoing benign gynecologic surgery. or structures with the potential to cause serious morbidity and complicate subsequent operations Materials and Methods (1). An accurate prediction of intraabdominal Local ethics board approval was granted for the adhesions would be extremely beneficial to help study. The ethics standards of the 1975 preventing injuries during the initial abdominal Declaration of Helsinki as revised in 2000 were entry. For this purpose, transabdominal followed. We performed a prospective cohort ultrasonography has been used to determine study of patients who underwent laparoscopic or intraabdominal adhesions. In 1991, Sigel et al. open gynecologic procedures for benign proposed a technique by observing the sliding indications in Bagcilar Training and Research movement of the abdominal contents for the Hospital between March 2017 and May 2018. detection of the intraabdominal adhesions (2). One hundred fifty-five patients were scheduled to Normally, the intraabdominal organs slide freely undergo a laparotomy (112 patients, 72.3%) or under the abdominal wall during normal laparoscopy (43 patients, 27.7%). Seventy (45%) respiration, a phenomenon named the "visceral

*Corresponding Author: Dogukan Yildirim, Halkali Merkez mah. Avrupa Konutlari 3 Sitesi 10/58, Kucukcekmece, Istanbul, Turkey E-mail: [email protected], Phone: 0(506) 328 43 83 Received: 12.10.2018, Accepted: 28.11.2018

Yildirim et al / Ultrasonographic prediction of adhesions

Table 1. Patient characteristics

Variable Data Number of patients, n 155 Age, mean (SD) 43.3 (8.9) BMI, mean (SD) 28.9 (6.1) Parity, median (range) 2 (0-12) Comorbidity, n (%) 21 (13.5) Any risk factor for adhesions, n 70 (45.2) (%) Patients with reduced visceral slide, 37 (23.9) n (%)

BMI: body mass index, SD: standard deviation Fig. 1. Sensitivity (Sens), specificity (Spec), positive patients had previous baseline risk factors predictive value (PPV) and negative predictive value (NPV) including abdominal surgeries, episodes of PID or of the visceral slide test in five zones peritonitis. Eighty-five (55%) patients had no risk and surgery results was performed by a third for intraabdominal adhesions. Patient independent investigator who was not involved in characteristics (age, body mass index [BMI], the ultrasound examination or the surgery. obstetric history, surgical history, history of PID, The sample size calculation was based on a indication for surgery, and comorbidities) are previous study with an incidence of 27% to 67% summarized in (Table 1). All patients were for adhesions after laparotomy (3). Based on the evaluated with an ultrasonographic examination of lower incidence (27%), the sample size required visceral sliding on the day of surgery. The for an alpha of 0.05 and a power of 80% was 70 ultrasound study was performed in the supine participants with a high risk of intraabdominal position using a Mindray DP-9900 Plus (Mindray, adhesions. Shenzen, China) 7.5 MHz abdominal transducer placed in a sagittal plane at the umbilicus and four abdominal quadrants; right upper quadrant Results (RUQ), right lower quadrant (RLQ), left upper quadrant (LUQ), left lower quadrant (LLQ). All All 155 enrolled patients underwent surgery, of ultrasound examinations were performed by the which 112 patients (72.3%) underwent same investigators (ISY and SY) whose results laparotomy, and 43 patients (27.7%) had a were blinded to the surgeons. Thus, the findings laparoscopy. The mean age of the women was of the ultrasound did not affect the decision of 43.3 ± 8.9 years. The mean BMI was 28.9 ± 6.1 the type of surgery (laparotomy or laparoscopy), kg/m2. In 35.5% of the patients (n=55), the BMI the types of incisions or the primary trocar sites. was ≥30 kg/m2. Indications for surgery in all A conventional gel was used between the groups included symptomatic uterine leiomyoma transducer and the skin to achieve acoustic (n=61), persistent adnexal mass (n=35), abnormal coupling. Each patient was examined during uterine bleeding resistant to medical treatment normal breathing with an exaggerated inspiratory (n=29), adenomyosis-endometriosis (n=16), and effort. Several cycles of respiration were observed, desire for tubal ligation (n=14). Seventy (45%) focusing on the deep layer of the abdominal wall patients had risk factors for intraabdominal to identify the vertical movement of the adhesions (previous abdominal surgery, episodes intraabdominal viscera. With uncooperative of PID or peritonitis). Eighty-five (55%) patients patients, visceral slide was induced by manual had no risk factors for intraabdominal adhesions. ballottement of the abdominal wall. Visceral slide When all five predefined zones were grouped, was measured using an electronic scale. Abnormal reduced visceral slide (<1cm) with ultrasound was visceral slide (negative test) was defined as no seen in 37 of 155 (23.8%) women. The resulting movement of the viscera or movement less than 1 sensitivity of the visceral slide test to detect any cm. The comparison of the ultrasound findings adhesion was 78.6% with a speciﬁcity of 88.2%,

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Table 2. Ultrasound and operative findings for the five defined zones

Intraoperative Findings

Ultrasound Findings Omental Bowel Absence of Adhesion Adhesion Adhesions (n=127) (n=22) (n=6) Reduced Visceral Slide 16 (72.7%) TP 6 (100%) TP 15 (11.8%) FP <1cm (n=37) Free Movement (n=118) 6 (27.3%) FN 0 FN 112 (88.2%) TN TN: true negative, TP: true positive, FN: false negative, FP: false positive with positive (PPV) and negative predictive values PPV 53.3% and NPV 95%. In the non-obese (NPV) of 59.5% and 94.9%, respectively. For only group (n=100, 64.5%), the results were the umbilical zone, visceral slide demonstrated a comparable; sensitivity 77.8%, specificity 90.2%, sensitivity of 70.6%, specificity of 90.6%, PPV PPV 63.6%, and NPV 94.9%. 48%, and NPV 96.2%. The results of the other There were two bladder injuries and one serosal four abdominal quadrants are presented in (Figure bowel injury, all of which were repaired 1). The performance of the visceral slide test is intraoperatively. None of them was related to the summarized in (Table 2). initial abdominal entry. During surgery, surgeons found 28 adhesions in five defined zones, most of which consisted of Discussion omental adhesions (22 of 28, 78.6%). In 10 of 28 patients (35.7%), adhesions were isolated in one Our study showed that preoperative ultrasound zone, and the remainder (n=18, 64.3%) had imaging of the visceral slide is highly reliable in multiple zone adhesions. There were adhesions predicting anterior abdominal wall adhesions, with within the umbilical zone in 17 patients: 6 with a sensitivity of 78.6%, NPV of 94.9% and overall bowel adhesions and 11 with omental adhesions. diagnostic accuracy of 86.5%. All of these six patients with bowel adhesions had Intraabdominal adhesions are mostly diagnosed undergone previous midline laparotomy incisions. intraoperatively. A suspicion of intraabdominal The visceral slide test was able to detect all six adhesions in the preoperative phase would bowel adhesions with a sensitivity of 100%, improve planning of the entry site for laparoscopy specificity of 79.2%, PPV 16.2%, and NPV 100%. or laparotomy. This concept is extremely For subgroup analyses, all patients were divided important in laparoscopy because the initial entry into two groups as follows: group 1, 85 patients is usually performed blindly. Blind trocar entry (55%) with no risk factors, and group 2, 70 may lead to complications, and 75% to 82% of patients (45%) with a risk factor for laparoscopy-related complications result from the intraabdominal adhesions. Four of 28 adhesions insertion of the ﬁrst trocar (4,5). Complications were found in the no-risk group (group 1), are seen mainly in patients who have a risk factor consisting of only mild omental adhesions, with a for intraabdominal adhesions. In 68.9% of cases prevalence of 4.7% (4 in 85 cases). Eighteen of bowel injuries in laparoscopy, adhesions or omental and six bowel adhesions were found in previous abdominal surgeries were documented in the high-risk group (group 2), with a prevalence of a literature review (6). The ability to predict the 34.3% (24 in 70 cases). The visceral slide test presence of such adhesions would help the showed a sensitivity of 75% in group 1 vs. 79.2% surgeon to minimize the risk of entry in group 2, specificity 90.1% in group 1 vs 84.2% complications in laparoscopy. in group 2, PPV 27.3% in group 1 vs. 73.1% in Ultrasonography is a simple and non-invasive group 2, and NPV 98.6% in group 1 vs. 88.6% in imaging modality available for all surgical group 2. specialties. The visceral slide test using A further subgroup that included only women ultrasonography was first described by general with BMI >30 kg/m2 (n=55, 35.4%) was also surgeons for detecting intraabdominal adhesions analyzed to assess the use of the visceral slide test in 1991 (2). Kolecki et al. found that the in obese patients. The sensitivity of the visceral sensitivity and speciﬁcity of the visceral slide test slide test was 80% with a specificity of 84.4%, to predict abdominal wall adhesions were 90 and

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92%, respectively (7). Steitz et al. reported similar that a positive test (free visceral movement) results, however, both studies were conducted in a corresponds to a high probability that the patient non-blinded fashion (8). Kothari et al. were the has no abdominal wall adhesions. However, it first to report blinded data on the visceral slide should be pointed out that 47% of our patients (8 test. They found a sensitivity of 43%, specificity of of 17) with surgically confirmed umbilical 90%, and overall accuracy of 78% (9). adhesions also harbored LUQ adhesions. Tu et al. used the visceral slide test in gynecologic Therefore, both the umbilicus and Palmer's point surgeries and found a sensitivity of 86% and should be evaluated separately to provide a safe specificity of 91% below the umbilicus (10). In a entry site for laparoscopic operations. recent study, Nezhat et al. found that a The strength of this study was its prospective and preoperative visceral slide test had a sensitivity of blinded design. The first blinding was between the 83.3%, specificity of 96.8%, PPV of 71.4%, and investigators and surgeons so that the visceral NPV of 98.54% (11). In contrast to these studies, slide test did not affect the surgeons' choice on we found a seemingly lower sensitivity (70.6%) the type of surgery. The second blinding was and PPV (48%), but similar specificity (90.6%) achieved in the validation period by allowing a and NPV (96.2%) for the umbilical zone. third independent investigator to make the However, the visceral slide test was able to detect comparison of the ultrasound and surgery results. all six bowel adhesions in the periumbilical area There were also limitations to the study. We had with a sensitivity of 100%, specificity of 79.2%, difficulties in differentiating bowel and omental PPV of 16.2%, and NPV of 100%. adhesions with the visceral slide test, we were only In a multicenter study, Aubé et al. showed that the able to document whether the test was positive or visceral slide test had a sensitivity and specificity negative. of 79% and 75%, respectively (12). They The visceral slide test is an easy, non-invasive and speculated that the low sensitivity and specificity reliable method for predicting abdominal wall of their results were because the majority of their adhesions. This useful test could help gynecologic patients were overweight. However, in our surgeons choose a safe entry site to the abdomen subgroup analysis, we found similar results and may reduce entry-related complications in between obese (BMI >30 kg/m2) and non-obese laparoscopy or laparotomy. patients. Conflict of interest: The authors report no conflict We had 15 cases of false-positive results; a of interest related with this study. restricted visceral slide test on ultrasonography Acknowledgements: The authors have received no but no adhesions in surgery. Seven (46.7%) of the funding for this article. 15 patients were obese, and 7 (46.7%) had a risk factor for intraabdominal adhesions. Two (67%) References of three patients with very large myomas exceeding the pelvis also had a false-positive tests. We think that the use of the visceral slide test is 1. Randall D, Fenner J, Gillott R, et al. A Novel Diagnostic Aid for Detection of Intra- not helpful in patients with very large myomas. Abdominal Adhesions to the Anterior We had 6 cases of false- negative results; free Abdominal Wall Using Dynamic Magnetic movement of the visceral organs but adhesions in Resonance Imaging. Gastroenterol Res Pract surgery. Four (67%) of the 6 patients had risk 2016; 2016: 2523768. factors for intraabdominal adhesions, and 3 (50%) 2. Sigel B, Golub RM, Loiacono LA, et al. were obese. Technique of ultrasonic detection and In laparoscopic surgery, the umbilicus is the most mapping of abdominal wall adhesions. Surg common insertion site for the first trocar. If Endosc 1991; 5: 161-165. adhesions are predicted in the periumbilical area, 3. Brill AI, Nezhat F, Nezhat CH, Nezhat C. The surgeons will generally choose Palmer’s point incidence of adhesions after prior laparotomy: (upper left quadrant) as the site of initial trocar a laparoscopic appraisal. Obstet Gynecol 1995; 85: 269-272. entry, because this point is thought to be free of adhesions or go for a laparotomy. We found that 4. Molloy D, Kaloo PD, Cooper M, Nguyen TV. Laparoscopic entry: a literature review and the visceral slide test with ultrasonography was analysis of techniques and complications of highly specific and had a high NPV for both areas, primary port entry. Aust N Z J Obstet with a specificity of 90.6% and NPV of 96.2% for Gynaecol 2002; 42: 246-254. the umbilical zone, and a specificity of 96.6% and NPV of 98.6% for Palmer's point. This indicates

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